Centerless grinding machine



Oct. 22 1929. H. w. HOLMES CENTERLESS GRINDING MACHINE Original Filed Nov. 25, 1925 {5 Sheets-Sheet J/arold hflblmes Oct. 22, 1929. V w HQLMES 1,733,095

CENTERLES S GRINDING MACHINE Original Filed Nov. 25, 1925 6 Sheets-Sheet 2 319.1 7 gin wanton (Harold WJ/Obnes GQq W OCL22, 1929. w HOLMES 1,733,095

CENTERLES S GRINDING MACHINE Original Filed Nov. 25, 1925 6 Sheets-Sheet 5 gwwwto'o Jfarald hJ/oLmes Oct. 22, 1929. H. w. HOLMES CENTERLESS GRINDING MACHINE Original Filed Nov. 25, 1925 6 Sheets-Sheet 4 Harold \MJ/olmes Oct. 1929- H. w. HOLMES 1,733,095

CENTERLESS GRINDING MACHINE Original Filed Nov. 25, 1925 6 Sheets-Sheet 5 gnmwtoz I (Harold h/(zfolmes 61cm mag .Oct. 22, 1929. H HOLMESv 1,733,095

CENTERLES S GRINDING MACHINE Original Filed Nov. 25, 1925 6 Sheets-Sheet 6 WITNESSES INVENTOR 7 Harold WJ/olmes BY @tv ATRNEY Patented Oct. 22, E929 OFFICE HAROLD W. HOLMES, OF DETROIT, MICHIGAN, ASSEGNOB, BY I'YIESNE ASSIGNMENTS, TO CINCINNATI GRIH'DERS ENCORPOEEAIED, G1 CINCINNATI, OHIO, A CORPORATION OF OHIO CENTER/LESS GRINDER MACHINE Application filed November 25, 1925, Serial No. 713%. Renewed March 1, 1929.

This invention relates to grinding and more particularly to apparatus for grinding cylindrical work or work of round section wherein the work is held or supported between a grinding wheel and a work regulating wheel for respective grinding and rotating action thereon.

One of the objects of this invention is to provide a thoroughly practical apparatus for grinding cylindrical work pieces or work pieces or" round section but which have shoulders, flanges or the like thereon. It has heretofore been proposed to grind cylindrical bodies in a grinding machine having a grinding wheel and a work regulating wheel between which the work is supported or held, the cylindrical bodies being rotated, and fed axially, by the regulating wheel during the grinding operation thereon by the grinding wheel; such an apparatus is capable of achieving high accuracy of grinding, as well as a high rate of production of accurately ground work, but is not adapted for grinding shouldered or flanged work which, because of the peculiar shape of the work, cannot be fed axially past the grinding wheel. One of the dominant aims of this invention is to provide an apparatus of the above-mentioned general. nature capable of grinding shouldered or irregularly shaped work pieces and in which, even though such work pieces cannot be fed axially past the grinding wheel, a high degree of accuracy of grinding and a high rate of production may be successfully achieved.

Another object is to provide an apparatus of the above-mentioned nature capable of achieving a high degree of eh'iciency and of achievin great economy in time, labor and cost in W incling at high accuracy and to a uniiorm size work pieces of shouldered or irregular shape.

Another object is to provide a grinding apparatus of the above-mentioned nature characterized by a high degree of reliability and dependability in operation, great ruggedness or". construction, and great flexibility of control operation, thus to readily meet the varying conditions of practical use. Another object is to provide an apparatus in which, even though the Work pieces may not be fed in an axial direction past the grinding wheel, due, for example, to their shape, high speed and substantial continuity of grinding, together with a high degree of safety of opation, not only to the operator but also to the work pieces operated upon and the mechanism itself, may be achieved in a thoroughly practical and dependable manner. Another object is to provide apparatus of the aboverncntioned character in which a high degree surface finish of the work pieces may be achieved in a thoroughly practical and dependable manner.

Another object is to provide a grinding apparatus in which the work piece, such as a shouldered work piece, may be dependably and accurately related operatively to the grinding wheel and regulating wheel in a manner minimizing accidental contact of the work piece with the grinding wheel, and to provide apparatus in which the removal of the work piece out of operative relation to the wheels may be achieved rapidly and without danger of marring the finished work piece by contact with the grinding wheel.

Another object is to provide a grinding apiiarat-us and mechanism for achieving substantially continuous grinding operations upon work pieces of irregular or shouldered shape and for achieving such substantial conti iuity of grinding production in a manner which, while capable of being achieved fully automatically, may be nevertheless dependably and reliably carried out under manual control.

Another object of this invention is to provide an apparatus of the above-mentioned (.1 I cal section respectively which will be indicated in the following claims.

In the accompanying drawings in which is shown by way of example an illustrative embodiment of my invention,

Fig. 1 is a side elevational view, a portion of which a centerless shown in section, of grinding); machine embodying; i e invention;

Fig. 2 is a side elevational view of certain mechanisl'i'is, embodied in the machine of Fig. 1, shown in a somewhat dia runimatical manner to more clearly indic ie their re lation to each other and to the grinding wheel and reggjulating wheel;

F 3 is a diagrammatical plan view of the mechanism shown in 1? 2;

Fin. 4: is a diagramn'iatical front elevational View of the mechanism shown in Fig. 5 is a detail view of part 0 anism shown in Fig. 2;

Fig. 6 is a detail view of a portion of the f the mechtripper mechanism;

Fig. 7 is a sectional view along the line 7-7 of 3;

Fig. 8 is a sectional view along; the line .88 of Fig. 2;

Fig. 9 is a detail view of the mechanism for automatically operating; the work supply magazine;

bodiment of my invention in which the aprparatus is fully automatic in operation, but,

as will he made more clear hereinafter, it will be understood that the machine may be operated in a semiautomatic manner and in such case all of the mechanisms thus shown may not be employed. llhe invention, although broader in its scope, is illustrated is embodying; a machine in which a regulating and work supporting wheel is arranged beneath and peripherally opposed to the grinding wheel, thus to achieve certain thoroughly practical advantages. This machine comprises a frame 10 (Fig. 1) within which mounted a grinding wheel spindle 11 carrying; a grinding wheel 12. The grindi wheel spindle 11 is rotated r pidly in direction indicated by the arrows in the various figures of the drawings, from a suitable source of power by a belt 13 passing over a pulley ll secured upon the spindle 11. A. column 15 may be moved vertically within a cylindrical portion of the frame 10, to which it is keyed, by means of a hand wheel (not shown) keyed to the shaft of a worm 16 meshing; with a worm wheel 17 keyed to a screw soaft 18 engaging; threads in a boss 19 integral with the frame. A regulating wheel 20 is mounted, beneath and peripherally opposed to tl grinding wheel, upon a spindle 21 for rotation in suitable bearings (not shown) and enclosed within the bearing casing; 22 supported upon the block 23 mounted upon the upper portion of the column 15 and normally fixed thereto but adapted to turn about the pivot 24. The regulating wheel 20 may be rotated relatively slowly from any suitable source of power and in the direction indicated by the arrows in the several views of the drawings. Thus, a motor 25 may be connected directly to a shaft 26 having a worm 9.7 thereon meshing with a worm wheel 28 upon the regulating wheel spindle 21.

An auxiliary frame support 30 fined on the column 15 (and movable therewith) extends upwardly in the rear of the regulating wheel 20. A. work holding member or blade 31 is slidably mounted in a carriage 32 movable vertically relative to frame 30 by virtue of the portions 33 engaging the vertical slide-- ways 3a in the frame 30. The carriage 39. may be moved vertically by means :of the pinion 35 meshing with the rack 36 secured upon the carriage The member 31, which determines the position of or supports the work piece between the wheels, may be snitably adjusted into parallelism with, and maintained with its work contacting edge or face parallel to, the axis of the grinding" wheel, such as by means of a pair of pins 37 each suitably supported and em the member 81 at one end and a cam 38 at the other end, thereby assuring that the work-contacting surface of the member 31 always parallel to the axis of the mind ing wheel as it is moved in andv out fo with work of different sizes. The cam arrangement just described is not per se my invention and is described. in detail and claimed in the co-pending application filerial No. 91,861 of Fred M. Kern ant Ii Seward. tiled lifarch 19%, and to that application reference may be had for further details of the construction and action thereof. A. ater pan 39 is secured to the support 23.

In accordance with certain features of the invention, one of the wheels may be moved toward or away from the other wheel to facilitate feeding worlr between the wheels, grindit to a predetermined size and subse qucntly discharging the ground work. This may be accomplished and I may achieve a xand C) and the cam 52, and that the parts number of great advantages, by mounting the grinding wheel so it may be moved periodically toward and away from the other wheel. Thus, the grinding wheel spindle 11 carried in a tapered split bearing 42 (see Fig. 8) is adjustably mounted within the trunnion 43 and has its axis located eccentric to that of the trunnion. The latter has a cylindrical bearing surface 41 mounted for rotative oscillation about its axis in the frame 10, (see Figs. 7 and 8) and is provided with a rearwardly extending arm 44 having an adjustable roller 45 positioned therein adapted to ride upon an arm 46. The roller 45 (see 2) is held by a member 47 which is adapted to be moved within a slot 48 in the arm 44 by means of an adjusting screw 49. The arm 46 is pivoted at one end to turn about a shaft 50 and has a cam roller 51 at the other end adapted to ride upon the peripheral surface of a cam 52 fixed upon the camshaft 53. A relatively heavy weight 54 (Fig. 1) is suspended by a rod 55 from the end of the arm 44 and serves LO hold roller 45 on the arm 46 and to hold the cam follower 51 upon the cam 52. The inter-relation and coaction of the arm 44 with the arm 46 and immediately associated parts, whereby a wide variability of the action of the fixed cam 52 may be achieved by varying the position of the roller lengthwise of the arm 44, are not per so my invention but permit the achievement, in coaction with the other parts of the apparatus herein described, of many important admntages, and they are described in detail and cla med in the co-aending application Serial No. 85,790 of Fred M. Kern, tiled nebruary 3, 1926, and to that application referenze may be made for further details of the construction and action thereof.

It will be observed that the center of the eccentric trunnion 43 (indicated at the int r section of the lines A and C in Fig. 7) is between the center of the grinding wheel spindle 11 (indicated by the intersection of lines B so arranged that rocking movement of he trunnion moves the grinding wheel in the substantially vertical portion of an arc. The cam 52, as shown diagrammatically in 16, is so shaped as to cause the grinding wheel 12 to move abruptly into an approximate grinding position and then to move gradually to grind the work, the wheel then being withdrawn relatively quickly to its initial position.

This cam may of course be variously shaped in accordance with the type of operation desired, but as illustrated it has spiral face which, as the same rotates, moves the cam roller 51 relatively gradually from a point a to a higher point 5 to feed the grinding wheel into the work. The grinding wheel then d Yell upon the work while the cam roller L ll 51 contacts wita the portion between the points Z) and c which are substantially equidistant from the cam shaft 53. From points 0 to (Z on the cam 52 the cam roller 51 drops away rapidly and then climbs the incline cZa, thus moving the wheel rapidly away from the work, due to the portion cd and then due to portion da moving the wheel towards the work.

The lateral thrust on the grinding wheel spindle 11 due to pulley 14 (Fig. 3) is taken by a roller race 55 (Fig. 8) suitably positioned in the trunnion 43 as illustrated. The pulley 14 is secured upon one tapered end of the grinding wheel spindle 11 by means of a nut 57, and the grinding wheel 12 is secured upon the other tapered end by means of a nut 58, in accordance with the usual practice.

In order that the grinding wheel may be oscillated axially through a slight distance to eliminate grain markings, the spindle 11 is mounted for reciprocation lengthwise through the bearings 42 and 55 (Fig. 8). This movement is preferably caused by a cam connected through a rocking arm and yoke to the spindle. As illustrated, the spindle has a yoke collar 59 fixed thereon, and this collar has a groove 60 for the insertion of a yoke 61 (Fig. 7) which is keyed to a shaft 62 supported for rocking movement in a hearing in the trunnion 43 as shown in Fig. 7.

A crank arm 63 is keyed to the outer end of the shaft 62 and is provided with a cam roller 64 which is adapted to engage the radial face of a cam 65 mounted upon the camshaft 53. The radial face is provided with a raised portion 66 suitably placed thereon to move the grinding wheel spindle axially, through the above-described coacting mechanism during grinding of a work piece. I preferably provide (see Fig. 17) but one raised portion 66, and the remainder of the cam face is plane, so that toward the end of the grinding operation the wheel will be given a single quick, short, axial move ment to smooth over the work surface. In Figure 7, the relation of the cam 65 with its raised portion 66 to the cam 52 will be seen to be such that, considered with respect to the respective cam followers, the axial movement of the grinding wheel 12 takes place substantially at or toward the end of the grinding operation. The arm 63 is held by suitable means such as a spring 631 (Fig. 3) so that the cam roller presses against the cam face and the wheel is held in one position except as moved by the cam.

In order that work pieces may be fed between the wheels in a systematic and dependable manner, I provide a power operated work moving mechanism which is constructed and arranged to feed the pieces separately and successively to a position for grinding and to achieve certain peculiarly advantageous coactions with the wheels, particularly the regulating wheel. This mechanism may be employed in a machine of the a o in nature above-described in which the wheels are relatively fixed, or in such a machine in which one wheel is moved relative to the other to grind the work to size, depending upon various factors and upon the advantages desired to be achieved. In the latter and prefer-rod case, the work is moved into position in such a timed relation rela ive to the movement of the wheel as to permit discharge of the finished work piece and a new piece of work to be presented to the wheels when the latter are separated, a peculiarly advantageous feature of coaction being hereinafter pointed out. One suitable mechanism for this purpose comprises an arm 67 (see Figs. l, 3 and 9) mounted to swing about a vertical pivot secured in brac at 69 mounted n1 in the right hand side of the water pan oil. The work moving arm 67 is provided near its outer end with a work carrying tray 79 slidably supported on spaced slidewa vs on the bottom of the arm which are inclined upwardly and rearwardly, shown in Fi 10 and 11. The tray '70 is provided at its lower or front end with a downwardly crtending lug (Fig. 2) adapted to contact v: steps 71 and 72 upon a bracket 78 secured to the hearing casing 22 of the work regula wheel 20 (see Fig. 1). As the arm 67 moves away from the wheel, the downwardly projecting lug of the tray 70 strikes against the stop 71 causing the tray to move relative to the arm to a position beyond the front work heldiu' memhei: on blade 7 3'', as seen in 12. When in this position the tray 70 is adapted to receive a work piece thereon and to hold the latter in advance of member 74:, the latter being mounted and acting hereinafter more clearly described. As the arm 67 moves toward the wheels the lug or tray 70 strikes against the stop 72, as seen in Figure 14;, which, in halting the tray 70 while permitting continued movement of arm 67, causes Such a relative movement between the tray and the arm as to effect substantially a withdrawal of the tray 70 from the arm 6 by this time, however, the arm 67 and its coacting parts have approached the upper surface of the regulating wheel 20 so that the work piece in elfect rolls or is dropped upon the regulating wheel 20 and substantially against the rear work holding member or blade 31, and is thus positioned for grinding by the grinding wheel. 12. The relative change in relation of the parts will be clear by comparison of 13 and l accordi i h the ferred embodiention, the arm 87 is actuated 1, 8, l and 5) mounte iii. arm 76 (Fi 1 and fl) is keyed one end t. a shaft 77 and is provided at its other end with a cam roller 7 8 adapted to engage the peripheral surface of the cam 7 A second arm 79 also is keyed at one end to the shaft 77 and is provided at its other end with a block 80 pivoted in the arm 7 9 to slidably engage a rod 81. The rod 81 is secured at one end to the movable arm 6. (Fig. 3) and is threaded at the other end for adjustable nuts 82 which hold a spring 83 upon the rod and in contact with the block 80, this spring serving as a safeguard in case an obstruction tends to prevent the arm 67 from swinging properly through its cycle. A spring 84 *ig. 1) is fastened between the front of the water pan 39 and the arm 67 for maintaining the cam roller 78 in contact with the peripheral surface of the cam and to move the arm away from the wheels as permitted by the cam. The cam 75 may be shaped as shown in Fig. 16 and it is located on the shaft 53 relative to the cam 52 so that the arm through the mechanism carried thereby will feed a new piece of work to the wheels '2 hile the grinding wheel 12 is moved away the regulating wheel 20 and so that the 1 6, for a purpose hereinafter described, 'emain stationary during the grinding once the cam 75 has a gener- :lar outline between the points 6 and 7 to hold arm 67 stationary and it is cut away to provide the face 6 g f which causes the man to swing. The movement of the arm 67 relative movements between the s n obviously be timed as desired, but I have shown the cams so arranged that the arm 67 will swing away just as the grinding operation is completed, the purpose of which will be made clear hereinafter.

Coact-ing with the work moving arm 67 and supper the water pan 39. A long cam 87 (Figs. 3, 4i and. 9) is formed integral with the arm 67 and extends substantially parallel with the direction of movement of the swinging arm 67 toward and away from the wheels. The care roller 88, secured at the free end of an arm 89 pivoted to the relatively fixed or stationary bracket 88, is adapted to be actuated by the cam 87 as the arm 67, in moving towards and away from the wheels, swings the cam relative to the roller 88. The arm 89 is adapted to be moved vertically and carries the upwardly extending lingers 90, which project through an openin in the magazine 85 (Fig. el) and. engage the work pieces therein. The lower open end of the magazine 85 is posi tioncd so as to permit a work piece to drop upon the arm 67 when it is away from the wheels (see Fig. 15). The cam 87 is so formed 9) that, when the arm 67 is in about osit on, the fingers 90 are in their lowertion, hence out of engagement with t no. the work pieces, and so release the work pic 3.

em 90 are forced upwardly to k pieces (see the raised portion of the cam 87 in Fig. 9) and to prevent further movement thereof down the chute or magazine 85. The arm 67 also has an upwardly extending ridge 91 4) to ena e the shoulder or end of the work iece on the arm 67 and prevent it from moving endwise out of proper grinding position.

The front work holding member or blade 74 10 and 11) is positioned in a recess 92 in the arm 67 and pressed rearwardly (to the right as viewed in Figs. 10 and 11) by a spring 93 which serves to absorb any impact between the member 7 4 and the work to and acts, furthermore, to yieldingly cause the member 74 to move the Work piece to into operative relation to the rear work holding member 31, thus holding it ready for grinding by the grinding wheel 12. A cover 94 serves to hold the spring 93 and the blade 74 in the recess 92 in the arm 67.

The camshaft 53 may be rotated by means of a worm 95 on the shaft 96 (Figs. 2 and 1) meshing with a worm wheel 97 fixed upon the camshaft 53. The shaft 96 may be rotated from any appropriate source of power, preferably by means of a belt 98 passing over a clutch pulley 99 on the shaft 96.

lprefer to provide a variable speed mechanism for rotating the drive shaft 96 (Figs. 2, 3 and 4) andconsequently the cam shaft 53 at a speed which may be selected at will. Thus, a belt 100, driven from any appropriate source of power and passing over a pulley 101, may drive the shaft 102 at any suitable speed. The power thus supplied to the shaft 102 may be transmitted to a shaft 103 (from an appropriate pulley on which the belt 98 and pulley 99 are driven) through a belt 104 which connects the cone or stepped pulleys 105 and 106 on the shafts 102 and 103 respectively. By means of the belt-connected cone pulleys 105 and 106, the speed or rate at which the cyclic operations of the mechanisms take place under the control of the cam shaft 53 may be predetermined or selected at will. A suitable toothed clutch 107, which is keyed to but slidable with respect to the shaft 96, is provided (see Fig. 2) for connecting the clutch pulley 99 to drive the shaft 96 and hence the worm 95.

The clutch 107 is moved to engage or disengage the pulley 99 by a preferably manually controlled cam operated mechanism. A suitable mechanism for this purpose (Figs.

2 and 6) may include a clutch yoke having hubs 109 and 110 pivotally mounted upon the shaft 77. An arm 111 extends rearwardly from the hub 109 and is provided with a V- shaped projection 112 on its end (Fig. 2). The projection 112 is adapted to contact with the V-shaped end projection 113 on pin 114 slidably mounted in aboss 115 in the frame of the machine. A spring 116 (Fig. 3) maintains a contact between the V-surfaces of end projections 112 and 113. A fork 117 extends downwardly and forwardly from the hubs 109 and 110 and carries a pair of pins 118 (Fig. 6), adapted to ride in a groove in the clutch member 107 (see Fig. 2). A double link 119 projects forwardly and is secured at one end (the right-hand end as viewed in Figs. 2 and 6) to the fork 117 and is supported near the other end (the left-hand end as seen in Fig. 2) by a downwardly extending arm 120 of a bell crank 121 pivotally mounted upon the shaft 50. A vertically positioned rod 122 having a slot 123 is mounted to slide upon a pin 124 in the forward end of the double link 119. The rod 122 is secured at its lower end to a link 125 which is keyed to a shaft 126 mounted in the frame of the machine for rotary movement by a clutch operating lever 127 the latter is secured upon the shaft 126 so that movement to the left, as viewed in Fig. 2, will swing the link 125 in counter-clockwise direction and move the rod 122 upward relative to the double link 119 (the slot 123 permitting this action) to strike against the forwardly extending arm 128 of the bell crank 121 and thereby turn the bell crank to move the double link 119 and the fork 117 forward (to the left as viewed in Figs. 2 and 6) and thereby bring the clutch 107 into engagement with the pulley 99 to rotate the shaft 96 and through it to rotate the camshaft 53. The latter thus becomes effective to operate cyclically the seveal mechanisms above described.

The lever 127 is provided with a spring plunger 130 (Fig. 4) which may engage openings 131 (Figs. 1 and 2) in a plate 132 secured upon the outside of the frame of the machine. The plate 132 may also be provided with a pair of stops 133 (Fig. 3). Thus the movements of the lever 127 and the shaft 126 about the axis of the latter may be limited between two extremes. The lever 127 is provided at its upper end with a forwardly directed projection 134 (see Figs. 2 and 6) for coaction with a projection 135 on a tripper V cam 136, which is mounted upon the cam shaft 53. If the rod 122 is moved by lever 127 into a position approximately that shown in Figs. 2 and 6, the projection 134 is thereby placed in the path of movement of the projection 135 upon the clockwise rotating tripper cam 136 and the projection 135on the'latter may engage the projection 134 or lever 126 to move the double link 119 to the right as seen in Figs. 2 and 6 and thereby ellect disengagement of the clutch 107 and the pulley 99. Thus, the cyclic operation of the several mechanisms controlled by the cam shaft 53 may be halted.

In the operation of the machine, the grinding wheel 12 is rotated rapidly from any appropriate source of power by means of a belt 13 (see Fi 1) passing over the pulley 14 on the grinding wheel spindle 11. The regulating wheel 20 is rotated relatively slowly through shaft 26 and worm and worm wheel 27 and 28, from the same source of power as the grinding wheel, or by means of a motor 25. The directions of rotation of the two wheels are indicated by the arrows in the drawings. With the pulley 99 rotating at a desired speed, selectable at will through the speed change mechanism 10 l;-105106 (Fi i), the cam shaft 58 may be set into rotation by pulling the lever 12? to the left, 1 s

viewed in Fig. 2, thus raising the rod 122 tostrike against the arm 128 of the belt crank 121; This throws the double link 119 forward and brings the clutch 10'? into operative engagement with the pulley 99.

With the lever 12? in this position and hence rod 22 in upper position, it will be noted that the projection 13 1 on the rod 122 is above and out bf the path circumscribed by the projection 135 on the tripper cam 136 so that the machine may operate complete y automatic. Thus, the cam shaft 53 together with the cams 52, and thereon may rotate uniformly and continuously with the cam rollers 51., tit and 7 8 in contact therewith respectively to actuate their various mechanisms, namel' i moving the grinding wheel; 12 toward away from the regulating wheel 20, for operating the work moving arm 67 and its as ociated mechanisms cyclically to l to grinding position and to release therefrom successiv'e pieces of work, and for reciprocating the grinding wheel axially during grinding of the work.

Considering the operation of each of these mechanisms separately, it will be noted that the rotation of the cam 2 (l ig.

a n d l) raises and lowers the cam roller 51 to raise and lower the free end of the pivoted arm 16 and the latter in turn raises and lowers the cam roller 15 with its associated arm 1 1. The latitude of movement of the arm td may be reduced or increased by adjusting the position of the cam roller 15 lengthwise on the arm M by turning the adjusting screw 49 to more the member 17, which holds the cam roller 45, within the slot 18, either nearer to or tarther he from the axis (shaft 50) of arm movement of the arm 4s: causes a tur g movement of the tri'innion 493 to change 1.110 position of the axis of the grinding wheel spindle 11, the latter being. as will be clear from the foregoing, eccentrically n'iounted in the trunnion 4.3, thereby causing the grinding wheel 12 to move cyclically towards and away from a suitable position for grinding work pieces to a predetermined size.

The cam roller 6 1 (Figs. 7 and 1 1-), maintained in contact with the projection 66 and the radial face of the cam 65 by means of the spring 631 (Fig. 3), causes a reciprocation of the arm 63 and yoke 61, and consequently an axial reciprocation of the grinding wheel spindle 11, in character depending on the shape of the cam face. In the preferred embodiment of this invention, the grinding wheel 12 is fed or moved directly into the work without axial oscillation. The cam 52, which feeds the wheel 12 into the work, is so shaped as to give a relatively rapid movement of the wheel toward the work to (as by the portion from (Z to a of Fig. 16) and then a continuous but relatively slow feeding motion thereto (as by the portion from a to b) and then at the end of this feeding motion to give a dwell (by the portion 6 to 0) to the wheel, which allows any spring of the parts to be taken out and also allows a sparkingout operation that tends to produce a better finish. During the time that the grinding wheel is held against the work or during this period of dwell of the cam, the grinding wheel spindle is oscillated. However, there is preferably only one oscillation; that is while the grinding wheel is dwelling against the work, the wheel is moved about 1/8 of an inch away from the shoulder on the work piece and again brought back to position as will be clear from the action of cam 65 and its relation to that of cam 52. This oscillation tends to take out any lines or scratches or wheel marks.

At the same time the cam 75 (Figs. 2 and 5) is rotated uniformly causing predetermined oscillation of the arm 75, the shaft 77, and also the arm 79, thus to move the rod 81 and cause movement of arm 67 first away from and then towards the wheels. During this movement, the cam roller 88 (Fi 9, st and 3) on the arm 89 is continually in contact with the cam 8'? on the arm 67. The 'am 87 is shaped that while the arm 67 is moving away from the wheels, the fingers 9O l and are lowered to release a work piece from the magazine and permit it to slide onto the top of the arm as shown in Fig. 15. Then when the arm 67 moves toward the wheels, the fingers 90 (Figs. 4 and 9) are caused to move upward and engage the n Fit? to the last work piece so as to assure that only one piece is per nitted to drop from the magazine onto the carrier arm. The movement of the work to including its passage from the magazine 85 to a grinding position between the wheels, and its subse' quent discharge after being ground will be clearly understood by reference to 12 to 15 inclusive. As the arm 67 continues to move farther away from the wheels and left ward from the position shown in Fig. 15, the work piece rolls within the magazine while resting upon the top surface of the swinging arm until it is rolled (due to the movement of arm 67 relative to the fixed magazine 85) on to the top surface of the blade 74: and thence on to the tray 70 (see now Fig. 12), the latter having been moved in the meantime to the right relative to arm 65, because of its engagement with the adjustable stop 71. The work 10 will thus be seen, in Fig. 13, resting on tray 70 and in advance of the member 74. The arm 67 then moves towards the wheels, carrying the work as seen in Fig. 13, until the lug on the tray 7 strikes against the stop 72 (see Fig. 14) which retracts the tray and permits the work w to fall upon the regulating wheel. Further movement of the arm 67 towards the wheels causes the member 74 to push the work a ainst the rela tively fixed member 31 in position for grinding, as seen in Fig. 14. The member 74 pushes and holds the work to against and alined with the member 31, acting yieldingly due to the action of the spring 93 (Figs. 10 and 11) 5 the work w is thus held in proper position against the tendency of the slow moving surface of the regulating wheel 20 to move it to the left as viewed, for example, in Figs. 1 and 2. The subsequent movement downwardly of the grinding wheel 12, to efiect the grinding action on the work w, thus finds the work properly alined with and held in operative relation to the work holding mem ber 31. After the work is ground, the arm 67 and the work holding member 74 (which coacts with the Work holding member 31) move away from the wheels and release the ground work so that it may be discharged by rolling off the regulating wheel, as seen in Fig. 15. In the meantime, a new piece of work has under the control of the fingers descended the magazine chute to the position on the upper surface of arm 67 as shown in Fig. 14, whence the above described cycle is repeated. If the work has a shoulder, this hangs over the edge of the top surface of the arm 67 as shown in Figs. 14 and 15 and the work is prevented from moving endwise by the ridge 91 (see Fig. 9) while it is be ing carried to a grinding position.

After such a movement of the arm 67 towards the wheels as to position the work to substantially as shown in Fig. 14, the grinding wheel axis is moved to bring the grinding wheel into grinding relation with the regulating wheel and into grinding contact with the work. These two motions, however, are so timed that the work is always placed in grinding position in contact with the regulating wheel 20 before the grinding wheel 12 is permitted to come in contact therewith. The grinding Wheel and the arm 67 stay in the position thus attained until the work has been ground to a predetermined finished size and then move away from the regulating wheel, as previously described, to a position for again receiving work to be moved be tween the wheels in position for grinding. As the grinding wheel and the arm 67 move away from the regulating wheel, the ground work rolls off the regulating wheel and is discharged. v

The speed of the automatic movements above described may be increased or decreased so as to feed, grind and discharge work automatically at any desired rate by adjusting the bel 104 in an appropriate position upon the cone pulleys 105 and 106. Thus the work pieces may be ground at a most suitable rate which depends upon the character of the work and other such variable factors as will be readily understood by those skilled in the art.

If it is desired to operate the machine automatically for one complete cycle and then stop the automatic movements with the work moving member and the grinding wheel away from the regulating wheel, this may be accomplished by moving the lever 127 and hence rod 122 (see Fig. 2) to bring the projection 134 on the rod 122 to a predetermined location within the path circumscribed by the projection 135 upon the tripper earn 136. \Vith the projection 134 in this position, it will be observed that at the end of the cycle of the automatic movements, the projection 135 comes in contact therewith to move the double link 119 and the clutch yoke (to the right as viewed in F ig- 2) to disengage the clutch 107 from the pulley 99. The work piece is then placed in the tray 70 and the lever 127 drawn forward, or to the left as shown in Fig. 2, to cause rod 127 to rise and strike arm 128, thus to throw the clutch 107 in, thus to start the apparatus, as previously described. The lever 127, after starting, is then again moved to bring the projection 134 in an appropriate position to again stop the automatic movements after one complete cycle.

The automatic movements may be stopped, when necessary, with the wheels together in grinding relation, or in a suitable position for truing, by moving the lever to a suitable extent and to bring the projection 134 into an appropriate predetermined position within the path of the projection 135 on the tripper cam 136.

It will be observed that when the projection 135 of tripper earn 136 strikes against the projection 134 on the rod 122 to throw the double link 119 and the clutch yoke to the right, as seen in Fig. 2, the arm 111 is caused to turn about the shaft 77 and when the apex of the V-shaped end projection 112 coincides ith the apex of the V-shaped end projection 113, the inclined surface of the end projection 113 is forced by the spring 116 along the in clined surface of the end projection 112, thereby positively throwing the clutch out of en gagement with the pulley 99. A similar action takes place when the clutch is thrown in to start the automatic movements. The complete clutch-engaging and clutch-disengagin g movements are thus assured.

Normally, the spring 83 (Fig. 2) is under sufiicient compression to maintain the link 7 9 in a fixed position relative to the rod 81. However, if a work piece becomes clogged be tween the work moving member and the magazine, or if other emergency arises, the spring 83 is compressed a sufficient amount to prevent further movement of the arm 67 of the work moving mechanism, and thereby safeguards the mechanism against breakage and permits the operator to remove the cause of the irregularity of operation.

It will thus be seen that in this invention a grinding machine is provided which is par ticularly adapted for grinding shouldered work in a more economical and satisfactory manner than has heretofore been possible. Thus, inasmuch as the machine may be oper atod in a completely automatic manner, the work is always positioned accurately in an axial line parallel with the axis of the grind ing wheel. and in contact with the regulating wheel before the grinding wheel is brought into a grinding position. his assures proper grinding of the work and eliminates the clanger of injury to the work which might be oecasioned by moving the work into grinding position directly in contact with the grinding wheel. llioreover, the grin ding wheel is led into the work to take a definite depth of cut r in exactly the same manner when grinding each individual work piece. This achieves reliably the production of. large quantities of work ground uniformly to a predetermined size.

A grinding machine such as that constructed in accordance with the invention is particularly adapted for use by automotive mamrt'acturers, where accurate precision grinding and high rate of production are primary requisites. The machine of the invcntion makes possible greater production, inasmuch as work is fed to the machine and ground and then discharged therefrom in a systemn'latic, thoroughly practical, and dependable manner, and the -:;tent and quality of the production is not at all dependent upon human endeavor.

The machine eliminates the danger of injury to workmen inasmuch as it is seldom necessary for the operator to place his hands in proximity with a moving part. lVhen the machine is operating automatically, all that is required of the operator is to maintain a supply of work pieces in the magazine. Likewise, when the machine is operating in a semi automatic manner the operator places a work. piece on the work moving member when it is stopped away from the wheels and when the grinding wheel is out of grinding position. Moreover, in general, it will be noted that the machine of the invention eliminates the uncertainties accompanying rontine grinding heretofore and speeds up production to a marked extent without sacrifice of quality of grinding.

It will also be apparent that this invention, in its broader aspects is applicable to various types of center-less grinding machines, and that, while illustrated and described as ap plying to a machine in which peripherally opposed wheels are arranged one above the other, yet it is equally applicable to a ma chine having the wheels in other arrange ments, such as one in which the wheels are peripherally opposed and have their axes in substantially the same horizontal plane orone in which the disk face of: one or both wheels is employed. The changes required to adapt this invention to machine types not illustrated will be readily apparent to those skilled in the art.

As many possible embodiments may be made of the above invention. and as many changes might be made inv the embodiment above set forth, it to be understood that all. matter hereinbefore set, forth or shown in the accompanying drawings is to be in terpreted as illustrative and not in a limiting sense.

Having thus described my invention, what I claim as new and desire to secure by Lets Patent is:

l. A centerless grinding machine comprising a work regulating wheel and a grinding wheel, means for supporting worl; ther lmtwc n for grinding, means for rotating the gulating wheel slowly and the grinding wheel rapidly respectively to rotate and ..d the work, positively operated precill'ltlCllfllllSll'l for moving; the grinding wheel periodically towards and away from the re ulating wheel through a predeterininec distance, a mechanism constructed and (L' g; 3l l to move work pieces separately and ively into operative relation to said work supporting means and to said regulatwheel and thus into a position for grindand means for operating the work movmechanism cyclically in a pro erly timed .ation relative to the movement of the rinding wheel. so as to place a \VOFK piece grinding p sit-ion when. the wheels are separated and upon a subsequent separation of said wheels to permit discharge of the finished work.

2. A centerless grinding machine comprisa grinding wheel. a regulating wheel located beneath the grinding wheel, means for supporting work between said Wheels, means for rotating the regulating wheel slowly and the grinding wheel rapidly respectively to rotate and grind the work. a positively operated precision mechanism For moving one of the wheels periodically towards and from the other to grind the worn to a predetermined size and a cyclically operated mechanism operating in timed relation with the wheel movement to feed pieces of. work separately and successively onto said regulating wheel when the wheels are separated.

3. A centerless grinding machine comprisa grinding wheel, a. regulating wheel peripherally opposed to and located beneath the grinding wheel, work, holdingmeans to maintain the work in position for grinding, a positively operated precision mechanism for moving one of the Wheels periodically towards and from the other to grind a piece of work to a predetermined size, work carrying means arranged to move a piece of work laterally of its axis into position for grinding and to permit its release from contact with the wheels when finished and a cyclic mechanism to move the carrying means in timed relation with the wheel movement to feed the work to the wheels when they are separated.

4. A centerless grinding machine comprising a work regulating wheel and a grinding wheel, means for rotating the regulating wheel and the grinding wheel at speeds respectively to rotate and grind the work, a power operated cyclic mechanism constructed and arranged to move work pieces separately to a position between the wheels for respective rotation and grinding thereby, and manually controlled means for automatically stopping the mechanism after a complete cycle of operations in such a position that the finished work may be removed.

5. A grinding machine comprising a slowly rotated work regulating wheel and a rapidly rotated grinding wheel, means for moving one of the wheels periodically towards and from the other to permit the grinding wheel to grind the work to a given size during rotation thereof by said regulating wheel, a mechanism constructed and arranged to move work pieces separately to a position between the wheels for grinding, means for operating said mechanism in a uniformly periodic and properly timed re lation relative to said wheel movement to grind successive pieces of work and permit discharge thereof, and a power operated con trol device for bringing said wheel and work movement to a stop when the wheels are in a predetermined position.

6. A grinding machine comprising a work regulating wheel and a grinding wheel, means for rotating the regulating wheel and the grindig wheel at speeds respectively to rotate and grind the work, means for moving the grinding wheel periodically towards and from the regulating wheel, a mechanism constructed and arranged to move work pieces separately to a position for grinding, means "for operating the mechanism in a uniformly periodic and properly timed relation relative to the movement of the grinding wheel to grind the work and permit discharge thereof, and a control device which permits the machine to run continuously and cyclically or which may bring said mechanism and the wheel to a stop at predetermned positions.

7. A centerless grinding machine comprising a work regulating wheel and a grinding wheel, means for rotating the regulating wheel and the grinding wheel at speeds respectively to rotate and grind the work, a work moving member constructed and arranged to present Work pieces separately for grinding, a mechanism including a clutchv wheel and the grinding wheel at speeds re- V spectively to rotate and grind the work, a mechanism including a clutch for moving one oi? the wheels cyclically towards and away from the other to permit rotation and grinding of the work and permit discharge hereof, and a cam operated mechanism for disengaging the clutch to bring said wheel movement to a stop at a predetermined point.

9. A grinding machine comprising a work regulating wheel and a grinding wheel, means for rotating the regulating wheel and the grinding wheel at speeds respectively to rotate and grind the work, a work supply source, a cyclically operated work moving member constructed and arranged to move work pieces separately from said source to a position for grinding, and a cam controlled device associated with said member to release work pieces separately from said source for movement by said member into operative relation to said wheels.

10. A grinding machine comprising a Work regulating wheel and a grinding wheel, means for rotating the regulating wheel and the grinding wheel at speeds respectively to rotate and grind the work, a pivotally mounted work carrying member adapted to move work into operative relation to said wheels, means for moving said member cyclically, said member including a work carrying tray adapted to move relative thereto, and means for causing relative movement of said tray in timed relation to the movement of said member to carry work toward and discharge the same in a position for grinding.

11. A centerless grinding machine comprising a rapidly rotated grinding wheel, a slowly rotated regulating wheel, means to maintain a piece oi work between the wheels during grinding action thereon by said grinding wheel and rotation action thereon by said regulating wheel, means to move one of the wheels towards and from the other periodically to grind the work approximately to size and then permit the grinding wheel todwell and finish grind the work, and means to oscillate the grinding wheel axially only during such period of dwell.

12. In grinding apparatus, in combination, a tour-sided grinding throat in which work of round section is received for simultaneous grinding and rotation, said grinding throat including a grinding wheel rotatable at relatively high speed, a regulating wheel rotatable atrelatively low speed, said wheels being adapted to present adjacent operative surlaces traveling in opposite directions, a mem rating and approaching said wheels and for relatively separating and approaching said two members, thereby to permit a work piece to be inserted intoor removed'trom said grinding throat.

13. In grinding apparatus, in combination, a tour-sided grinding throat in which work of round section is received forsimultaneous grinding and rotation, said grinding throat including a grinding wheel rotatable at relatively high speed, a regulating wheel rotatable at relatively low speed, said wheels being adapted to present adjacent opera ive surfaces traveling in opposite directions, a member for holding the work in operative relation to said two wheels and adapted to take up the thrust of the grind ing wheel on the work, and a member spaced from said lirst mentirmed member for taking. up the oppositely directed'tln'ustof the regulating wheel on the work; power actuated meansi'or relatively separating and approaching said two wheels in recurring sequence, and means coactiing therewith for relatively separating and approaching said two members, thereby to permit a work piece to be inserted into or removed from said grinding throat.

14. In grinding apparatus, in combination, a tour-sided grinding throat inwhiclr work of round section is received for simultaneous grinding and rotation, said grinding throat including a grinding wheel rotatable at relatively high speed, a regulating wheel rotatable at relatively low speed, said wheels being adapted to present adjacent operative sur faces traveling in opposite directions, a member for holdii'ig the work in operative relation to said two wheels and adapted to take up the thrust of the grinding wheel onthe work, and a member spaced from said first mentioned member for taking up the oppositely directed thrustoi? the regulating wheel on the work; means for relatively separating. and approaching said wheels, and power actuated means operating intimed relation to said last-mentioned means for relatively separating and approaching said two members thcrel'iy to permit a work piece to be inserted into or removed from said grinding throat.

15. In grinding apparatus, in combination, a 't'our-sided grinding: throat in which work of round section is received for simultaneous grinding and'rotation, said grinding throat including a grinding wheel rotatable at relatively high speed, a regulating wheel rotatable at relatively low speed, said wheels being adaptedto present adjacent operative surfaces traveling in opposite directions, a member for holding the work in operative relation to said two wheels and adapted to take up the thrust of the grinding wheel on the work, and a member spaced from said first-ntientioned member for taking up the oppositely directed thrust of the regulating wheel. on the work; means for relatively appreaching and separating said two wheels; and power actuated mechanism for relativel-y separating and approachingsaid two members, said mechanism acting to relatively approach said two members prior to the completion of the approaching movementof said. two wheels and to relatively separate said two members after the separation of said two wheels.

16. In grinding apparatus, in combination, a tour-sided grinding threat in which work of round section is received for simultaneous grinding and rotation, said grinding throatincluding a grinding wheel rotatable at relatively high speed, a regulating wheel rotatable ati'clatively low speed, said wheels icing adapted to present adjacent operative surfaces traveling in opposite directions, a member for holding the work in operative relation to said two wheels and adapted to take up the thrust ofthegrinding, wheel on the work, and a member spaced from said first-mentioned member for taking up the oppositely directed thrust of the regulating wheel. on the work; means foinrelatively a l preaching and separatingsaid two wheels; power actuated mechanism or relatively separating and approaching said two. members, said mechanism acting to relatively approach said two members prior to the com pletion oithe approaching movementoi said two wheels and to relatively separate said two members after the separation of said two wheels; and means controlled by said. mechanism for halting theoperation thereof.

17. In grinding apparatus,.in combination, a four'sided grinding throat in which work of round section is received for-simultaneous grinding and rotation, said grinding throat including a grinding wheel rotatable at relatively high. speed, airegulating wheel rotatable at relatively low speed, said wheels being adapted to present adjacent operative surfaces traveling in opposite directions, a member for holding the work in operative relation to said two wheels and adapted to take up the thrust of the grinding wheel on the work, and a member spaced from said first-mentioned member for taking up the: oppositely directed thrust of the regulating wheel on the work; means for relatively approaching and separating said two wheels; power actuated mechanism for relatively separating and approaching said two members, said mechanism acting to relatively approach said two members prior to the completion of the approaching movement of said two wheels and to relatively separate said two members after the separation of said two wheels; a clutch for controlling the action of said mechanism; and means controlled by said mechanism for actuating said clutch.

18. In grinding apparatus, in combination. a four-sided grinding throat in which work of round section is received for simultaneous grinding and rotation, said grinding throat including agrinding wheel rotatable at relatively high speed, a regulating wheel rotatable at relatively low speed, said wheels being adapted to present adjacent operative surfaces traveling in opposite directions, a member for holding the work in operative relation to said two wheels and adapted to take up the thrust of the grinding wheel on the work, and a member spaced from said first-mentioned member for taking up the oppositely directed thrust of the regulating wheel on the work; means for relatively approaching and separating said two wheels; power actuated mechanism for relatively separating and approaching said two members, said mechanism acting to relatively approach said two members prior to the completion of the approach ing movement of said two wheels and to relatively separate said two members after the separation of said two wheels; means controlled by said mechanism for halting the operation thereof; and means for making said last-mentioned controlled means ineffective.

19. In grinding apparatus, in combination, a work regulating wheel rotatable at relatively low speed, a grinding wheel rotatable at relatively high speed, said wheels presenting adjacent operative surfaces traveling in opposite directions. said regulating wheel acting to rotate work of round section interposed between said two wheels, a blade-like member extending between said wheels for holding work of round section in operative relation thereof, a magazine for holding a supply of work pieces, a movable member adapted to effect movement of a work piece into operative relation to said blade-like member, thereby to present the work piece to the adjacent operative surfaces of said wheels, and means for presenting a work piece, one at a time, from said magazine to said movable member.

20. In grinding apparatus, in combination. a work regulating wheel rotatable at relatively low speed, a grinding wheel rotatable at relatively high speed, said wheels presenting adjacent operative surfaces traveling in opposite directions, said regulating wheel acting to rotate work of round section interposed between said two wheels, means for holding work of round section between said wheels, a magazine for holding a supply of work pieces, a power actuated reciprocating Y said reciprocating member.

21. In grinding apparatus, in combination, a grinding wheel adapted to be rotated at a relatively high speed, a regulating wheel positioned at a lower elevation than said grinding wheel and rotatable at a relatively low speed, thereby to control the rotation of work of round section interposed therebetween, said wheels being adapted to present adjacent operative surfaces traveling in opposite directions, means for holding work of round section between said wheels, and a member movable in a general horizontal direction adapted upon movement toward said work holding means to effect movement of a work piece into operative relation to the latter and to said wheels and adapted upon subsequent movement away from said work hold ing means to permit the work piece to substantially roll off of the surface of said regulating wheel.

22. In grinding apparatus, in combination, a work regulating wheel rotatable at relatively low speed, a grinding wheel rotatable at relatively high speed, said wheels presenting adjacent operative surfaces traveling in opposite directions, said regulating wheel acting to rotate work of round section interposed between said two wheels, means for holding work of round section between said wheels, power actuated mechanism including a clutch for moving a work piece into operative relation to said wheels, said mechanism being constructed and arranged to operate said clutch in a directionto halt said mechanism, and means for re-setting said clutch to make said mechanism operative.

28. In grinding apparatus, in combination, a grinding wheel rotatable relatively high speed, a regulating wheel positioned beneath said grinding wheel and rotatable at a relatively low speed, said wheels being adapted to present adjacent operative sur aces traveling in opposite directions, means for holding work of round section in operative relation to said adjacent operative surfaces of said two wheels, and means movable in a generally horizontal direction and adapted to effect a movement of a work piece into operative relation to said work holding means and to said wheels.

24. In grinding apparatus, in combination, a grinding wheel rotatable at relatively high speed, a regulating wheel positioned beneath said grinding wheel and rotatable at a relative low speed, said wheels being adapted to present adjacent operative surfaces traveling in opposite directions, means for bolding work of round section in operative relation to said adjacent operative surfaces of said two wheels, means movable in a general-- ly horizontal direction toward and away from said work holding means and adapted upon moven'ient toward said work holding means to effect a movement of a work piece into operative relation to the latter and to said wheels and to hold the work piece vagainst movement in reverse direction and adapted,

upon movement away from said work holding means to permit discharge of the work piece from the apparatus.

25. In grinding apparatus, in ('ol'nbination, a grinding wheel rotatable at relatively high speed, a regulating wheel positioned beneath said grinding wheel, and rotatable at a relatively low speed, said wheels being adapted to present adjacent operative surfaces traveling in opposite directions, means for holding work oii round section in operative relation to said adjacent,operative surfaces of said two wheels, means movable in a generally horizontal direction. toward and away from said work holdingmeans and adapted upon movement,toward said work holding means to effect a movement of a work piece into operative relation to the latter and to said wheels and upon movement away from said work holding means to permit discharge of the work piece from, the apparatus, a magazine for holding a supply of work pieces, and means for presenting work pieces one at a time from said magazine to said horizontally movable means.

26. In grinding apparatus, in combination a grinding wheel rotatable at relatively high speed, a regulating wheel positioned beneath said grinding wheel and rotatable at a relatively low speed, said wheels being adapted to present adjacent operative surfaces traveling in opposite directions, means for holding work of round section in operative relation to said adjacent operative surfaces of said two wheels, a magazine for holding a supply of work pieces, a power driven reciprocating means cooperating with said magazine and adapted to receive a work piece from the latter and eil'ect its movement into operative relation to said wheels upon movement in in one direction and upon movement in reverse direction to permit discharge of the work from the apparatus.

27. In grinding apparatus, in combination, a grinding wheel rotatable at relatively high speed, a regulating wheel positioned beneath said grinding wheel and rotatable at a relatively low speed, said wheels being adapted to present adjacent operative surfaces traveling in opposite directions, means for holding work of round section in operative, relation.

to said adjacent operative surfaces of said two wheels, a magazine for holding a supply of work p1eces,means movable m a generally horizontal direction adapted to receive a work piece from said magazine and move it toward said work holding means, and means operating in timed relation to said last-men tioned means for removing the work piece from the latter and for completing the movement of the work piece into operative relation to said wheels.

28. In grinding apparatus, in cmnbinati-on, a grinding throat adapted for simultaneous grinding and rotating action upon work of round section and comprising three means, one of which means is in the form of a grinding wheel adapted to be rotated. at a relatively high speed, another of said means being in the form of a regulating wheel adapted to be rotated at a relatively low s eed and in a direction to present an operative surface traveling in a direction opposite from that of the adjacent grinding wheel surface and adapted thereby to control the rotation of the.

work, and the third of which means includes a member for holding work of round section in operative, relation to said two wheels; power driven means adapted. in recurring se quence to change the relation of the grinding throat to the work, thereby to permit insertion or removal of a work piecewith respect to the grinding throat, and power controlled means for making inoperative said power driven means,

29. In grinding apparatus, in combination, a grinding throat adapted for simultaneous grinding and rotating action upon work of round section and comprising three means one of which means is in the form of a grinding wheel adapted to be rotated at arelatively high speed, another of said means being in the form of a regulating wheel adapted to be rotated at relatively low speed and in a direction to present an operative surface traveling in a direction opposite from that of the adjacent grinding wheel surface and adapted thereby to control the rotation of the work, and the third of which means includes a member for holding work of round section in operative relation to said two wheels; power driven means adapted in recurring sequence to change the relation of the grinding throat to the work, thereby to permit insertion or removal of a work piece with respect to the grinding throat, a clutch for controlling the operation of said power driven means, and means for automatically operating said clutch.

30. In grinding apparatus, in combination, a grinding throat adapted for sinniltaneous grinding and rotating act-ion upon work of round section and comprising three means, one of which means is in the form of a grinding wheel adapted to be rotated at a relatively high speed, another of said means being in the form of a regulating wheel adapted to be rotated at a relatively low speed and in a directionto present an operative surface traveling in a direction opposite from that of the adjacent grinding Wheel surface and adapted to control the rotation of the Work, and the third of which means includes a member for holding work of round section in operative relation to said two wheels; power driven means adapted in recurring sequence to change the relation of the grinding throat to the work, thereby to permit insertion or removal of a work piece with respect to the grinding throat, a clutch for controlling the operation of said power driven means, means for automatically operating said clutch, and manually controlled means for re-setting said clutch.

31. In grinding apparatus, in combina tion, a grinding throat adapted for simultaneous grinding and rotating action upon work of round section and comprising three means, one of which means is in the form of a grinding wheel adapted to be rotated at a relatively high speed, another of said means being in the form of a regulating wheel adapted to be rotated at a relatively low speed and in a direction to present an opera.-

tive surface traveling in a direction opposite from that of the adjacent grinding wheel surface and adapted to controlthe rotation of the work, and the third of which means includes a member for holding work of round section inoperative relation to said two wheels; power driven means adapted in recurring sequence to change the relation of the grinding throat to the work, thereby to permit insertion or removal of a work piece with respect to the grinding throat, and speed-change mechanism interposed in said power driven means and providing a plurality of different relative speeds any one of which is selectable at will for controlling at will the periodicity of operation of said power driven means.

32. In grinding apparatus, in combination, a grinding throat adapted for simultaneous grinding and rotating action upon work of round section and comprising three means, one of which means is in the form ofa grinding wheel adapted to be rotated at a relatively high speed, another of said means being in the form of a regulating Wheel adapted to be rotated at relatively low speed and in a direction opposite from that of the adjacent grinding wheel surface and adapted thereby to control the rotation of the work, and the third of which means includes a member for holding work of round section in operative relation to said two wheels; power actuated means for controlling the movement of a work piece with respect to said grinding throat and speed-change mechanism interposed in said power actuated means and providing a plurality of different relative speeds any one of which is selectable at will for controlling at will the periodicity of operation of said power actuated means.

33. In grinding apparatus, in combination, a grinding throat adapted for simultaneous grinding and rotating action upon work of round section and comprising three means, one of which means is in the form of a grinding wheel adapted to be rotated at a relatively high, speed, another of said means being in the form of a regulating wheel adapted to be rotated at a relatively low speed and in a direction to present an operative surface traveling in a direction opposite from that of the adjacent grinding wheel surface and adapted thereby to control the rotation of the work, and the third of which means includes a. member for holding work of round section in operative relation to said two wheels; a magazine for holding a supply of work pieces, power driven means adapted in recurring sequence to effect movement of a work piece from said magazine into said grinding throat, and speed-change mechanism interposed in said power driven means and providing a plurality of different rela tive speeds any one of which is selectable at will for controlling the periodicity of operation of said power driven means.

34. In grinding apparatus, in combination, a grinding throat adapted for simultaneous grinding and rotating action upon work of round section and comprising three means, one of which means is in the form of a grinding wheel adapted to be rotated at a relatively high speed, another of said means being in the form of a regulating wheel adapted to be rotated at a relatively low speed and in a direction to present an operative surface traveling in a direction opposite from that of the adjacent grinding wheel surface and adapted thereby to control the rotation of the work, and the third of which means includes a member for holding work of round section in operative relation to said two wheels; mechanism for cyclically changing the relation of the grinding throat to the work and for effecting a movement of a Work piece relative to the grinding throat, and means for automatically halting the operation of said mechanism at the completion of a cycle.

35. In grinding apparatus, in combination, a grinding throat adapted for simultaneous grinding and rotating action upon work of round section and comprising three means, one of which means is in the form of a grinding wheel adapted to be rotated at a relatively high speed, another of said means being in the form of a regulating wheel adapted to be rotated at a relatively low speed and in a direction to present an operative surface travel ing in a direction opposite from that of the adjacent grinding wheel surface and adapted thereby to control the rotation of the work, and the third of which means includes a member for holding work of round section in operative relation to said two wheels; mechanism for cyclically changing the relation of "the grinding throat to the work and for efiie'ctirrg a movement of a work plece relative to will for controlling at will the periodicity of operation of said mechanism.

36. In "Tllltlln a iaratus 1n combination a grinding throat adapted for simultaneous grinding and rotating action upon work of round section "and comprising three means,

1 one or which means is in the form of a grinding wheel adapted tobe rotated at a relatively high speed, another of said means he -ing in thel -orm olia regulating wheel adaptedto be rotated at a relatively low speed and in a direction to present an operative surface traveling in a direction opposite from :that or the adjacent grinding wheel surilace and a dapted thereby to control the rotation of the work, and the third. of which means i-ne'lu'desa member for holdiu work of round section in operative relation to said two wheels; mechanism for cyclically changing the relation o'l the grinding throat to the work and for eil'ecting a movement of a work piece relative to the grinding throat, means controlled by said mechanism for lurlting theoperation of thelatter, and means for makingsaid mechanism again operative.

' 37. In grinding apparatus, in combination, a grin ding throat adapted for simultaneous grin-ding androtating action upon work of round section and comprising three means, one oi. which means is in the form oi a grinding Wheel adapted to be rotated at a relatively highspeed, another of said means being in the form of a regulating wheel adapted to be rotated at a relatively low speed and in a direction to present an operative surfacetraveling in a direction opposite from that of the adjacent grinding wheel surface and adapted thereby to control the rotation of'the work, and the third oi? which means iincludesa member for holding work of round section in ope 'ative relation to said two "wheels; mechanism for cyclically changing the relation of the grinding throat to the "work and 'for eiiecting a movement of a workpiecerelative to thegrinding throat, a clutch for controlling the operation of said mechanism, said-mechanism being con- -structed and arranged to operate said clutch at'the completion of a cycle of operations by said mechanism, and means for re-setting said clutch.

38. In grinding apparatus, in combination, a grinding throat adapted for simultaneous grinding and rotating action upon work of round section and comprising three means, one of which means is in the form of a grinding wheel adapted to be rotate: at a relatively high speed, another of said means being in the form oi a regulating wheel adapted to be rotated at a relatively direction to present low speed and ma direction to present an operative surface traveling in a direction opposite from that of the adjacentgrinding wheel surface and adapted thereby to control the rotation of the work, and the third oi. which means includes a member for bolding work of round section in operative rela tion to said two wheels; mechanism for cyclically changing the relation of thegrinding throat to the work and for effecting a movement of a work piece relative to the grinding throat, a clutch for controlling the operation of said mechanism, means for automatically operating said clutcln means for manually operating said clutch, and means selectable at will for determining which of said clutch operating means is to be effective.

239. in grinding apparatus, in combination, a grinding throat adapted for simultaneous grinding and rotating action upon work of round section and comprising three means, one of which means is'in thei or-m of a grinding wheel adapted to be rotated at a relativelyhigh' speed, another of said means being in the form of a regulating wheel adapted to berotated at a relatively low speed and in a direction to present an operative surface traveling in a direction opposite from that of the adjacent grindingwhcel surface and adapted thereby to control the rotation of the work, and the third of which :means includes a member for holding work otround section in operative relationto said two wheels and power driven means inclu-dinga clutch for moving one of rid means to change the relation of the grinding throat to the work, said clutch being controlled by said power driven means.

40. In grinding apparatus, in combination, a grinding throat adaptedfor simultaneous grinding and rotating action upon work of round section and comprising three means, one of which means is in the form of a grinding wheel adapted to be rotated at a relatively high s1 eed, another of said means being in the form of a regulating wheel adapted to be rotated at a relatively low speed and in a an operative suriace traveling in a direction opposite from that of the adjacent grinding wheel surface and adapted thereby to control the rotation of the work, and the third of which means includes a member for holding work of round section in operative relation to said two wheels; and power driven means including a clutch for moving one of said means to change the relation of the grindingthroat to the W011i, means forautomaticallyoperating said clutch, means for manually operating said clutch, anc means adapted to permit selection at will ofsaid clutch operating means.

ll. In apparatus of the character described, in combination, a grinding throat adapted for simultaneous grinding and rotating action 

